Earlier filed patent application (PCT/AU02/00218), relates to a non-invasive method and apparatus for determining onset of physiological conditions such as hypoglycaemia, irregular BGL, SIDS and the onset of fatigue.
As disclosed in the PCT application:                It is desirable with some physiological conditions to be able to monitor a patient in a non-invasive manner so that when a physiological condition presents itself, an alarm signal is triggered. The alarm activation will enable the patient to take remedial action or medication to prevent that physiological condition causing harm to the patient.        Certain physiological conditions, such as hypoglycaemia can be extremely dangerous and in many cases the symptoms can occur without the patient becoming aware of his/hers low BGL. The drop in BGL can occur reasonably fast, hence, a fast and accurate monitoring of low BGL hypoglycaemia) is essential, particularly, when the BGL is being monitored indirectly. The indirect BGL measurement methodology occurs by the monitoring of certain physiological parameters, including, skin impedance, heart rate, certain components of the electrocardiogram (such as QT interval) and their subsequent rate of change over the time.        It is also desirable that monitoring these physiological parameters cause minimal discomfort to the patient. Since many patients will require to monitor the physiological conditions for long periods of time (e.g. throughout the night), it is important that the monitoring system can be set up and used with minimum inconvenience and discomfort to the patient.        
Prior art patent specifications have described various forms of belt or chest straps for monitoring certain physiological functions of the patient or user. For example one such belt is described and shown in U.S. Pat. No. 5,036,869, which uses chest belt with wireless telemetry system to transmit body signals from human body to a receiver. The body signals measured include electrode discharge detecting circuit, pacemaker signal detector, ECG and non-invasive sphygmomanometer (blood pressure measurement). These signals are then decoded and data processed by the receiver unit and interfaced to a generic measurement apparatus. The disclosed patent's claims are focused towards the telemetry platform of the system, and enhanced capability for measuring multiple body signals. Another patent described in U.S. Pat. No. 4,889,131 discloses a portable belt-type monitor which measures breathing and heart rate and produces an alarm signal when dysfunctions are detected. The alarm signals are then transmitted via wireless telemetry platform to a remote receiver unit. The core claims within this patent specification discuss the improved method of measuring ECG (or EKG) and respiration parameters. The claims also disclose a portable microcomputer system, with display, which can be attached to the described utility chest belt.
There are other chest-belt monitoring systems, including patents such as U.S. Pat. Nos. 5,464,021, 4,966,155, UK 2,291,505 and UK 2,368,645. In general, the devices and systems disclosed within these prior art specifications do not exhibit methodology and functionalities for detecting the early onset of certain physiological conditions. These prior art systems do not have the real-time analytical capabilities for detecting the onset of the physiological conditions.